Methods for additively manufactured identification features

ABSTRACT

Techniques for integrating a machine-readable matrix with a component of a mechanical structure using three-dimensional (3-D) printing are disclosed. Such techniques include generating at least one data model representing the component, and projecting a matrix pattern identifying one or more features of the component onto a selected surface portion of the component to produce a modified data model for use as an input to a 3-D printer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of, and claims priority to, U.S. patentapplication Ser. No. 15/677,734, filed Aug. 15, 2017, entitled “METHODSAND APPARATUS FOR ADDITIVELY MANUFACTURED IDENTIFICATION FEATURES,” nowallowed, which application is incorporated by reference in its entiretyas if fully set forth herein.

BACKGROUND Field

The present disclosure relates generally to data preservationtechniques, and more specifically to integrated data matrices inadditive manufacturing for facilitating the identification andpreservation of data relevant to additively manufactured parts.

Background

Manufacturers in various industries have increasingly used additivemanufacturing (“AM”) as a means to produce more complex andcost-efficient components. AM systems, also described asthree-dimensional (3-D) printers, can produce structures havinggeometrically complex shapes, including some shapes that are difficultor impossible to create with conventional manufacturing processes. Whilethese AM capabilities have broad application, they are especiallyprevalent in industries involving vehicles, boats, aircraft,motorcycles, and other transport structures

While producing components used in such structures, designers typicallycreate a 3-D representation or model of the component using acomputer-aided-design (CAD) program or similar application. The designermay create a custom representation of such a structure and/or use 3-Dmodels from libraries of standard parts. Thereafter, the designed partsmay be additively manufactured for further use or for assembly in alarger structure as appropriate.

During the course of these activities, designers and manufacturers ingeneral have become aware of the importance of maintaining accuraterecords and data relating to each of the multitude of AM parts. To tracksuch parts more efficiently, manufacturers often use barcodes or otheridentifiers affixed directly on the part. The barcode or otheridentifier may include information relative to one or more features ofthe item, such as its purpose, date and country of origin, intendeddestination, operating or assembly instructions, replacement date,instructions for assembly into a larger structure, and other pertinentdetails.

With the use of AM, however, new challenges have arisen in how to bestassociate these types of relevant data with AM components. Ordinarybarcodes may be inadequate for this purpose. While the CAD model of thecomponent is in 3-D, ordinary barcode data is in 2-D. This means that a2-D data matrix representing the barcode is not compatible with a 3-Dmodel of the corresponding AM product.

Conventional attempts to overcome this problem have included applying aseparately printed barcode as a flat adhesive label onto the part. Amongother deficiencies, this technique is both manually intensive andvulnerable to possible fraudulent activities such as label replacementand counterfeiting. Furthermore, such labels are ordinarily less durablethan the associated AM component and are therefore particularlyvulnerable to damage, vandalism, and tampering. These vulnerabilitieserode confidence in the reliability of the manually applied label.

Accordingly, new techniques are needed for facilitating the associationof relevant data with AM components.

SUMMARY

Several aspects of integrating data into AM components will be describedmore fully hereinafter with reference to three-dimensional printingtechniques.

One aspect of a method of integrating a machine-readable matrix with acomponent of a mechanical structure using three-dimensional (3-D)printing includes generating at least one data model representing thecomponent, and projecting a matrix pattern identifying one or morefeatures of the component onto a selected surface portion of thecomponent to produce a modified data model for use as an input to a 3-Dprinter.

One aspect of a component for use in a mechanical structure andthree-dimensional (3-D) printed based on at least one data modelincludes a 3-D structure configured to perform one or more intendedfunctions when assembled into the mechanical structure, and amachine-readable 3-D matrix pattern integrated on a selected surfaceportion of the 3-D structure and configured to identify one or morefeatures of the component.

It will be understood that other aspects of integrating data into AMcomponents will become readily apparent to those skilled in the art fromthe following detailed description, wherein it is shown and describedonly several embodiments by way of illustration. As will be realized bythose skilled in the art, integrating data into AM components arecapable of other and different embodiments and its several details arecapable of modification in various other respects, all without departingfrom the invention. Accordingly, the drawings and detailed descriptionare to be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of integrating data into AM components will now bepresented in the detailed description by way of example, and not by wayof limitation, in the accompanying drawings, wherein:

FIG. 1 is a flow diagram illustrating an exemplary process of initiating3-D printing.

FIGS. 2A-D illustrate an exemplary powder bed fusion (PBF) system duringdifferent stages of operation.

FIG. 3A is an example of a 2-D matrix code.

FIG. 3B is an example of a 2-D matrix code having a different polarityand that contains identical data to matrix code of FIG. 3A.

FIG. 4A shows an AM matrix projected to a 3-D surface facet inaccordance with an aspect of the present disclosure.

FIG. 4B shows a 2-D matrix projected onto a relatively flat surfacefacet of the 3-D model through translation, scaling, and rotation.

FIG. 5 is an example of a code pitch dimension as measured on the 2-Dmatrix of FIG. 3A.

FIG. 6 is a cross-sectional view of an extruded 3-D printed matrix madeintegral to an AM component.

FIG. 7 is a sensor view of an extruded 3-D matrix 700 with a flat topupper surface.

FIG. 8 is a cross-sectional view of a 3-D printed matrix having varyingsurface textures.

FIG. 9 shows an illustration of a code-reading operation of a texturedmatrix in accordance with the present disclosure.

FIGS. 10A-C show an illustration of variations of the matrix codereading process from three perspectives.

FIG. 11 shows a cross section of a matrix that has been exposed tocontamination.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended to provide a description of various exemplaryembodiments of integrating data into AM components and is not intendedto represent the only embodiments in which the invention may bepracticed. The term “exemplary” used throughout this disclosure means“serving as an example, instance, or illustration,” and should notnecessarily be construed as preferred or advantageous over otherembodiments presented in this disclosure. The detailed descriptionincludes specific details for the purpose of providing a thorough andcomplete disclosure that fully conveys the scope of the invention tothose skilled in the art. However, the invention may be practicedwithout these specific details. In some instances, well-known structuresand components may be shown in block diagram form, or omitted entirely,in order to avoid obscuring the various concepts presented throughoutthis disclosure.

The use of 3-D printing in the context of composite tooling providessignificant flexibility for enabling manufacturers of mechanicalstructures and mechanized assemblies to manufacture parts with complexgeometries. For example, 3-D printing techniques provide manufacturerswith the flexibility to design and build parts having intricate internallattice structures and/or profiles that are not possible to manufacturevia traditional manufacturing processes.

FIG. 1 is a flow diagram 100 illustrating an exemplary process ofinitiating an AM process. A data model of the desired 3-D object to beprinted is rendered (step 110). A data model is a virtual design of the3-D object. Thus, the data model may reflect the geometrical andstructural features of the 3-D object, as well as its materialcomposition. The data model may be created using a variety of methods,including 3D scanning, 3D modeling software, photogrammetry software,and camera imaging.

3D scanning methods for creating the data model may also use a varietyof techniques for generating a 3-D model. These techniques may include,for example, time-of flight, volumetric scanning, structured light,modulated light, laser scanning, triangulation, and the like.

3-D modeling software, in turn, may include one of numerous commerciallyavailable 3-D modeling software applications. Data models may berendered using a suitable computer-aided design (CAD) package, forexample in an STL format. STL files are one example of a file formatassociated with commercially available CAD software. A CAD program maybe used to create the data model of the 3-D object as an STL file.Thereupon, the STL file may undergo a process whereby errors in the fileare identified and resolved.

Following error resolution, the data model can be “sliced” by a softwareapplication known as a slicer to thereby produce a set of instructionsfor 3-D printing the object, with the instructions being compatible andassociated with the particular 3-D printing technology to be utilized(step 120). Numerous slicer programs are commercially available. Slicerprograms convert the data model into a series of individual layersrepresenting thin slices (e.g., 100 microns thick) of the object beprinted, along with a file containing the printer-specific instructionsfor 3-D printing these successive individual layers to produce an actual3-D printed representation of the data model.

A common type of file used for this purpose is a G-code file, which is anumerical control programming language that includes instructions for3-D printing the object. The G-code file, or other file constituting theinstructions, is uploaded to the 3-D printer (step 130). Because thefile containing these instructions is typically configured to beoperable with a specific 3-D printing process, it will be appreciatedthat many formats of the instruction file are possible depending on the3-D printing technology used.

In addition to the printing instructions that dictate what and how anobject is to be rendered, the appropriate physical materials necessaryfor use by the 3-D printer in rendering the object are loaded into the3-D printer using any of several conventional and often printer-specificmethods (step 140). Powder bed fusion (PBF), for example, is an AMtechnique that uses a laser or other power source, along with adeflector, to fuse powdered material by aiming the laser or power sourceautomatically at points in space defined by a 3-D model and binding thematerial together to create a solid structure. PBF includes within itsscope various specific types of AM methods. Selective laser melting(SLM) and selective laser sintering (SLS), for instance, are PBFtechniques in which print materials may be loaded as powders into apowder bed defined by a build plate and bordering walls (see FIGS.2A-D). Layers of powder are deposited in a controlled manner into thepowder bed for the power source to selectively manipulate on alayer-by-layer basis. Depending on the type of 3-D printer, othertechniques for loading printing materials may be used. For example, infused deposition modelling (FDM) 3-D printers, materials are oftenloaded as filaments on spools, which are placed on one or more spoolholders. The filaments are typically fed into an extruder apparatuswhich, in operation, heats the filament into a melted form beforeejecting the material onto a build plate or other substrate.

Referring back to FIG. 1, the respective data slices of the 3-D objectare then printed based on the provided instructions using thematerial(s) (step 150). In 3-D printers that use laser sintering, alaser scans a powder bed and melts the powder together where structureis desired, and avoids scanning areas where the sliced data indicatesthat nothing is to be printed. This process may be repeated thousands oftimes until the desired structure is formed, after which the printedpart is removed from a fabricator. In fused deposition modelling, partsare printed by applying successive layers of model and support materialsto a substrate. In general, any suitable 3-D printing technology may beemployed for purposes of this disclosure.

FIGS. 2A-D illustrate respective side views of an exemplary PBF system200 during different stages of operation. As noted above, the particularembodiment illustrated in FIGS. 2A-D is one of many suitable examples ofa PBF system employing principles of this disclosure. It should also benoted that elements of FIGS. 2A-D and the other figures in thisdisclosure are not necessarily drawn to scale, but may be drawn largeror smaller for the purpose of better illustration of concepts describedherein. PBF system 200 can include a depositor 201 that can deposit eachlayer of metal powder, an energy beam source 203 that can generate anenergy beam, a deflector 205 that can apply the energy beam to fuse thepowder, and a build plate 207 that can support one or more build pieces,such as a build piece 209. PBF system 200 can also include a build floor211 positioned within a powder bed receptacle. The walls of the powderbed receptacle 212 generally define the boundaries of the powder bedreceptacle, which is sandwiched between the walls 212 from the side andabuts a portion of the build floor 211 below. Build floor 211 canprogressively lower build plate 207 so that depositor 201 can deposit anext layer. The entire mechanism may reside in a chamber 213 that canenclose the other components, thereby protecting the equipment, enablingatmospheric and temperature regulation and mitigating contaminationrisks. Depositor 201 can include a hopper 215 that contains a powder217, such as a metal powder, and a leveler 219 that can level the top ofeach layer of deposited powder.

Referring specifically to FIG. 2A, this figure shows PBF system 200after a slice of build piece 209 has been fused, but before the nextlayer of powder has been deposited. In fact, FIG. 2A illustrates a timeat which PBF system 200 has already deposited and fused slices inmultiple layers, e.g., 150 layers, to form the current state of buildpiece 209, e.g., formed of 150 slices. The multiple layers alreadydeposited have created a powder bed 221, which includes powder that wasdeposited but not fused.

FIG. 2B shows PBF system 200 at a stage in which build floor 211 canlower by a powder layer thickness 232. The lowering of build floor 211causes build piece 209 and powder bed 221 to drop by powder layerthickness 232, so that the top of the build piece and powder bed arelower than the top of powder bed receptacle wall 212 by an amount equalto the powder layer thickness. In this way, for example, a space with aconsistent thickness equal to powder layer thickness 232 can be createdover the tops of build piece 209 and powder bed 221.

FIG. 2C shows PBF system 200 at a stage in which depositor 201 ispositioned to deposit powder 217 in a space created over the topsurfaces of build piece 209 and powder bed 221 and bounded by powder bedreceptacle walls 212. In this example, depositor 201 progressively movesover the defined space while releasing powder 217 from hopper 215.Leveler 219 can level the released powder to form a powder layer 225that has a thickness substantially equal to the powder layer thickness232 (see FIG. 2B). Thus, the powder in a PBF system can be supported bya powder support structure, which can include, for example, a buildplate 207, a build floor 211, a build piece 209, walls 212, and thelike. It should be noted that the illustrated thickness of powder layer225 (i.e., powder layer thickness 232 (FIG. 2B)) is greater than anactual thickness used for the example involving 150 previously-depositedlayers discussed above with reference to FIG. 2A.

FIG. 2D shows PBF system 200 at a stage in which, following thedeposition of powder layer 225 (FIG. 2C), energy beam source 203generates an energy beam 227 and deflector 205 applies the energy beamto fuse the next slice in build piece 209. In various exemplaryembodiments, energy beam source 203 can be an electron beam source, inwhich case energy beam 227 constitutes an electron beam. Deflector 205can include deflection plates that can generate an electric field or amagnetic field that selectively deflects the electron beam to cause theelectron beam to scan across areas designated to be fused. In variousembodiments, energy beam source 203 can be a laser, in which case energybeam 227 is a laser beam. Deflector 205 can include an optical systemthat uses reflection and/or refraction to manipulate the laser beam toscan selected areas to be fused.

In various embodiments, the deflector 205 can include one or moregimbals and actuators that can rotate and/or translate the energy beamsource to position the energy beam. In various embodiments, energy beamsource 203 and/or deflector 205 can modulate the energy beam, e.g., turnthe energy beam on and off as the deflector scans so that the energybeam is applied only in the appropriate areas of the powder layer. Forexample, in various embodiments, the energy beam can be modulated by adigital signal processor (DSP).

As noted above, parts that are additively manufactured are typicallydesigned as part of a 3-D data model. By contrast, typical data matricesare a mathematical model of a flat, two-dimensional, binaryblack-and-white surface pattern similar to a printed paper label. Theseproperties make such a data representation incompatible for integrationinto AM components. To avoid such incompatibilities and the conventionaldeficiencies discussed above with respect to conventional solutions, themethod herein broadly contemplates directly associating the matrixpermanently into the AM part in an immutable way.

FIG. 3A is an example of a 2-D matrix code 300. Matrix codes are symbolsthat require regions with high contrast relative to one another, such aslight zones 302 and dark zones 304, to enable good legibility.Conventionally, good legibility has been attained by printing black inkonto a light-colored label, a process that generally yields a strongcontrast. This conventional approach involves a two-step process tofirst produce the label—namely, make the paper tab and mark itaccordingly—and second to attach the label to the component. Processdeviations in design and manufacturing, and in field use including themalicious influences described above, can introduce unpredictable errorsor result in tampering activities.

FIG. 3B is an example of a 2-D matrix code 306 that contains identicaldata to matrix code 300 of FIG. 3A. The matrices 300 and 306 have thesame pattern and internal shapes, but differ with respect to theirbright-dark polarity. For example, shapes 306A and 306B are the same butwith dark inverted to light and vice versa. Similarly, shapes 308A and308B are the same but with light inverted to dark and vice versa. Thisgeneral polarity reversal pattern persists throughout matrices 300 and306. The matrix polarity is not relevant to the reader in the sense thatboth polarities may be interpreted to read as the same data text. Inshort, information is conveyed in these labels because the dark andlight zones in the matrices 300 and 306 create contrast when viewed by abarcode reader. This information may be included in the location of thelight-dark transitions.

In one aspect of the disclosure, a 3-D machine-readable data matrixintegrated into an AM component is disclosed. In an embodiment, thetechniques as described herein integrate the steps described above withreference to FIGS. 3A-B into a single AM step and permanently integratethe data matrix into the shape of the original AM component. In theinitial design process, a 3-D matrix pattern may be integrated into apart. This is accomplished by projecting a 2-D pattern of the matrixinto 3-D space and onto the plane of an identified surface of a 3-D datamodel. Using this technique, the matrix pattern can be translated androtated to be rendered consistent with the part's relevant surfacefacet. In an embodiment, a part may be scaled in order to accommodate arelatively flat facet area for this purpose.

FIG. 4A shows a 2-D AM matrix 400 projected onto a 3-D surface facet inaccordance with an embodiment. The 2-D matrix 400 is shown segmentedinto black and white zones 402. However, it will be appreciated thatcolors may in some instances not be realizable or available during theAM process. The projection of FIG. 4A may be accomplished by selecting adesirable flat surface facet area on the 3-D component to be additivelymanufactured and projecting the matrix pattern onto the surface facet ofthe 3-D model.

In an embodiment, the particular location on the part is selected forits visibility and accessibility, whether with the part in isolation orwith the part as assembled into its operating position within a largerstructure, such as a vehicle. This facet selection may involve tradeoffsor design compromises. For example, the part as designed may not have asuitable surface facet. In this case, the part may in some instances beredesigned to incorporate a flat area to accommodate this feature.Further, while there may be accessible and visible flat surface facetsfor the isolated part, the part as assembled into a larger structure maynot have any accessible such surface facets. Accordingly, in someembodiments, various design changes may be considered and implemented inorder to facilitate a view of the matrix on the part. In short, changesmay be required to present a suitably visible surface facet to act as amachine-readable label or nameplate on a moving part. These and otheraspects may be taken into consideration during the design phase of theAM process.

In one embodiment, the matrices generated may be compatible with allreader types, including a barcode type reader, LED and laserillumination readers, ambient techniques, lens-based imaging, scanning,and the like.

FIG. 4B shows a 2-D matrix 404 projected onto a relatively flat surfacefacet of the 3-D model through translation, scaling, and rotation. Afterthese steps, the projected matrix has been elevated such that regionscorresponding to light zones 406A (FIG. 4A) have been elevated as shownby region 406B (FIG. 4B) and may be 3-D printed at the part surface 410.Conversely, regions corresponding to dark zones 408A (FIG. 4A) may beinset as shown by region 408B (FIG. 4B) into the part surface 410. In anembodiment, readable contrast may be created using any one or more ofthree techniques. First, a surface texture differential may be generatedto reflect illumination differently (see FIGS. 8-11). Second, shadowsmay be generated in areas of varying elevation using differential blockillumination. For this technique, elevations above and below the surfacemay cast shadows that darken certain areas such that, for example, uppersurfaces may be illuminated and appear bright, while lower surfaces maybe shadowed and appear dark. Vertical wall surfaces may be obscured byrelatively sharp normal reading angles relative to the surface of theprojected matrix. Third, coloration or infill such as paint may be usedas a post-processing step.

As is evident from matrix 404 of FIG. 4B, the dark zones 408B of thematrix pattern may be projected downward vertically to form a prismaticindentation below the part surface. This effect forms a relieved 3-Drepresentation of the matrix into the surface of the data model. Theresulting matrix 404 may resemble a carving on the part surface. Insetdark zones 408B may create shadows that produce matrix contrast. Lightzones 406B may remain elevated at surface level and may cast shadowsinto the dark zones 408B. This shadowing effect exploits the offsetbetween the illuminator and the sensor, which offset may vary but insome embodiments may be approximately 15-45 degrees. In general, atlarger illumination offsets and deeper inset distances, this shadowingeffect may create readable contrast.

FIG. 5 is an example of a code pitch dimension 502 as measured on the2-D matrix 500 of FIG. 3A. Code pitch dimension 502 is defined as thesmallest discrete unit on the matrix. Code pitch dimension 502determines the spatial resolution of the encoded information in thematrix. This dimension generally sets the limit of standoff distance andreadability for barcode readers and camera sensors that can read thedata in the matrix 500.

FIG. 6 is a cross-sectional view of an extruded 3-D printed matrix 600made integral to an AM component. Code pitch dimension CP (602) isrepresented in this embodiment by a cross-sectional width of thesmallest feature in the matrix. FIG. 6 also shows relief depth dimensionRDD (604), which defines the well depth to which the matrix pattern maybe inset below the AM component surface. In this exemplary embodiment,the relief depth dimension is two code-pitch lengths such that RDD=2×CP.Thus, in one embodiment, the inset below the AM part surface may be setsuch that the relief depth dimension is twice the code pitch. It will beappreciated that this quantity is illustrative in nature, and otherdimensions may be equally suitable.

While a native matrix material may be selected and used during thecomponent's AM process to form the readable matrix pattern, this patternmay not provide an optical contrast between the matrix and base 606.That is, because these homogenous zones exhibit no contrast between darkand light areas, the matrix may not be readable to a sensor or barcodereader. For example, in the cases of black-on-black or white-on-whitemarking, the low contrast may not be visible. Thus, in accordance withanother aspect of the disclosure, contrast-enhancing features may beincorporated into the component data model and integrated with the AMprocess of the component.

FIG. 7 is a sensor view of an extruded 3-D matrix 700 with a flat topupper surface. The matrix 700 includes light zone 702 and dark zone 704and has a similar pattern as the matrix of FIG. 3A. In this example, thematrix pattern 700 has been formed into the homogenous material of thesubject component. Dark zone 306A of FIG. 3A corresponds to dark zone704 in FIG. 7. Similarly, light zone 308A of FIG. 3A corresponds tolight zone 702 in FIG. 7. The apparent contrast between dark and lightzones relative to a sensor viewing the matrix at an angle substantiallyorthogonal to the matrix surface may be poor, having been lost as aside-effect of the AM process. Thus, in this instance, it may bedifficult or impossible for a reader to reliably find the matrix or toread the data content encoded therein.

In one embodiment, a more deeply inset pattern may be used to recoversome of the lost resolution. In another embodiment, in cases where theAM component is not capable of providing a deeper pattern or where sucha pattern is otherwise impractical, dark and light areas may beprogrammed having different textures. In an exemplary embodiment, asurface texturing contrast creation mechanism is employed. Contrast maybe created, for example, through differential texturing incorporatedinto the surface of the AM matrix. The texture may interfere with theillumination either constructively or destructively as describedhereinafter, thereby creating dark and light zones.

FIG. 8 is a cross-sectional view of a 3-D printed matrix 800 havingvarying surface textures. In this embodiment, dark and light areas maybe programmed with different textures. The surface finish and texturedtopography of a textured matrix may interact with illumination of areader to produce a strong contrast and a reliable, readable matrixsymbology pattern. The matrix 800 may include a part surface 802, aspecular well zone 804, and a textured zone 806. The part surface 802may be planar or relatively flat. If no matrix were printed, the partsurface 802 would extend uniformly flat across the top of the figure. Inthis example, the matrix 800 is formed entirely by eliminating materialbelow the part surface 802. However, in other embodiments, matrices canalso be formed at the part surface 802 or elevated and protruding abovethe part surface 802. Recession below the surface to well zones 804 maybe advantageous in some instances because the indented shape of texturedzones 806 may provide protection of the matrix symbols and patternsagainst frictional wear and tear and other trauma.

The textured zones 806 may reflect light at different angles than themore indented well zones 804. This effect may be enhanced at certainviewing angles as a result of the obscuration and shadowing caused bymatrix recession. The relieved geometry of the matrix 800 and itstextures may be arranged to create visible contrast under most lightingconditions with both structured and ambient light. Effective contrastmay therefore be achieved under a variety of common viewing conditionsand the matrix reading process may be made more reliable as a result.

FIG. 9 shows a code-reading operation of a textured matrix 900 inaccordance with the present disclosure. An illumination source 902 maygenerate light 903 that is directed onto the AM component andcorresponding matrix 900. The matrix 900 may include a plurality ofcanted ridges 906 and recessed wells 908. The light 902 may be reflecteddifferentially off canted ridges 906 and recessed wells 908. Thereflected light 920 may thereupon be scattered differentially by the twotextures and respective elevations. This scattering may create acontrasting pattern between the light and dark zones of the matrix 900.

The pattern of reflected light and dark areas constituting the matrixsymbology may be received by sensor 904. Thereupon, an image of thematrix pattern may be formed in the sensor and processed to extract itssymbolic content and geometric metadata including, for example, 3-Dposition, 3-D orientation, etc.

FIGS. 10A-C show an illustration of variations of the matrix codereading process from three perspectives. FIGS. 10A-C show illuminators1002A-C and sensors 1004A-C, respectively. Referring initially to theexample of FIG. 10A, matrix 1010 includes textured surfaces 1008 andspecular well zones 1006. As shown, sensor 1004A is at an offset viewingangle relative to matrix 1010 and illuminator 1002A is on axis withsensor 1004A such that illuminator 1002A directs light to matrix 1010 atsubstantially the same angle as sensor 1004A receives it. The sensor1004A and illuminator 1002A are in a nearly coaxial position and thefield of illumination is nearly coincident with the field of view ofsensor 1004A. Thus, because the light 1012 is coincident with texturedsurfaces 1008, reflected light 1014 from textured surfaces 1008 isbright and specular well zones 1006 are dark, which may correspond to anormal polarity.

More specifically, as illuminator 1002A emits light 1012, the texturedsurface 1008 of matrix 1010 may reflect light 1014 from bright zonesinto the sensor 1004A and the specular well zones 1006 may deflect light1016 in a different direction. A readable contrast is thereby achieved.

Referring to FIG. 10B, sensor 1004B is at a normal (orthogonal) viewingangle relative to matrix 1020 and illumination of light 1014 fromilluminator 1002B is on axis with sensor 1004B. Thus, because thedirection of light 1014 is normal to specular well zones 1006 ratherthan the textured surfaces 1008, the textured surfaces 1008 in thisembodiment are dark, the specular well zones 1006 are bright, and thepolarity is inverted. Here, light 1022 from the specular well zones 1006may be reflected directly back to sensor 1004B. The dashed lines 1016represent the angle of any illumination differentially reflected fromdark textured surfaces 1008, which is advantageously different from theangle at which light 1022 is reflected from bright specular well zones1006. A good readable contrast may be achieved in this example as well.

Referring to FIG. 10C, sensor 1004C is at a normal viewing anglerelative to specular matrix 1030 and specular well zones 1006.Illuminator 1002C is off-axis relative to sensor 1004C by an angle θ. Inthis example, light 1032 from illuminator 1002C arrives at angle θsubstantially coincident with textured surfaces 1008. The texturedsurfaces 1008 consequently may reflect light 1034 directly toward theviewing angle of sensor 1004. By contrast, light 1030 reflected from thespecular wells 1006 may be differentially reflected away from a viewingangle of sensor 1004C. Thus, in this embodiment, textured surfaces 1008are bright, specular wells 1006 are dark and the polarity is normal. Agood readable contrast may be achieved in this situation.

In another aspect of the disclosure, a technique for reducingcontamination exposure in 3-D integrated matrices is disclosed. Inaddition to creating visible contrast, matrix recession such as in theembodiment of FIGS. 10A-C may improve resistance to contamination.Contamination of surfaces may be common, for example, in outdoorenvironments where the part may be exposed to dirt, grease, road dustand the like. Accumulated contamination may potentially obscure orinterfere with the operation of sensors 1004A-C or other devices thatmay be used read the matrix symbology.

FIG. 11 shows a cross section of a matrix 1100 that has been exposed tocontamination. The matrix includes component surface 1100, well zones1104A-C, and textured zones 1106A-B. As is evident from theillustration, well zones 1104A-C and textured zones 1106A-B haveindentations where contaminants may accumulate. Two of the well zones1104B-C have been exposed to a contaminant 1108. Similarly, one of thetextured zones 1106 b has been exposed to a contaminant 1110. Thecontaminating substance may include, for example, substances like dirt,grease, mud, or other fine granular foreign substances. Thecontaminating substance may further include some mixture of organic andinorganic materials.

As is further evident from the illustration, one of well zones 1104A andone of textured zones 1106A are free from contamination. Well zone 1104Ais deeper than the indentations in textured zones 1106A-B. Further, wellzone 1104C is wider than the indentations in textured zones 1106A-B. Forthese reasons, well zones 1104A and 1104C may be able to sustain agreater accumulated bulk of contaminated material before becomingcorrupted. Similarly, well zones 1104A and 1104C may also accommodatelarger particles with larger overall grain size. Because the identifiedwell zones are deeper and/or wider, the bulk of contamination maytherefore accumulate in the well zones 1104A and 1104C and not in thetextured surfaces 1106A-B.

Particulate matter generally scatters light broadly, as opposed to therelatively flat and smooth specular surfaces of the AM component. Thesmall amount of contaminated material 1110 captured in textured surface1106B may therefore be relatively insignificant. This feature providesan inherent difference in optical characteristics of the relativesurfaces, which in turn may translate to a strong contrast between thelight and dark zones. To this end, accumulated contamination mayactually reinforce and improve the readability of the matrix symbologyproduced according to these embodiments. This optical feature furtherreinforces immunity to contamination and therefore overall reliabilityof the integrated matrix.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these exemplary embodiments presented throughout thisdisclosure will be readily apparent to those skilled in the art, and theconcepts disclosed herein may be applied to other techniques forintegrating 3-D matrices into parts. Thus, the claims are not intendedto be limited to the exemplary embodiments presented throughout thedisclosure, but are to be accorded the full scope consistent with thelanguage claims. All structural and functional equivalents to theelements of the exemplary embodiments described throughout thisdisclosure that are known or later come to be known to those of ordinaryskill in the art are intended to be encompassed by the claims. Moreover,nothing disclosed herein is intended to be dedicated to the publicregardless of whether such disclosure is explicitly recited in theclaims. No claim element is to be construed under the provisions of 35U.S.C. § 112(f), or analogous law in applicable jurisdictions, unlessthe element is expressly recited using the phrase “means for” or, in thecase of a method claim, the element is recited using the phrase “stepfor.”

What is claimed is:
 1. A method of integrating a machine-readable matrixwith a component of a mechanical structure using three-dimensional (3-D)printing, comprising: generating at least one data model representingthe component; and projecting a matrix pattern identifying one or morefeatures of the component onto a selected surface portion of thecomponent to produce a modified data model for use as an input to a 3-Dprinter.
 2. The method of claim 1, further comprising 3-D printing thecomponent including the projected matrix pattern using the modified datamodel.
 3. The method of claim 1, wherein the projecting the matrixpattern comprises at least one of translating, scaling, and rotating thematrix pattern relative to the selected surface portion.
 4. The methodof claim 1, wherein the projecting the matrix pattern comprisesconverting a two-dimensional (2-D) matrix pattern into a 3-D matrixpattern on the selected surface portion.
 5. The method of claim 1,further comprising adding a plurality of surface textures to the matrixpattern.
 6. The method of claim 1, further comprising varying anelevation of selected portions of the matrix pattern to create amachine-readable contrast.
 7. The method of claim 6, wherein at leastone elevated portion appears brighter to a machine reader and at leastone portion lower than the at least one elevated portion appears darkerto the machine reader to thereby create the machine-readable contrast.8. The method of claim 1, further comprising adding coloration to thematrix pattern.
 9. The method of claim 1, further comprising adding aninfill to the matrix pattern.
 10. The method of claim 1, wherein theprojecting the matrix pattern comprises integrating a 3-D matrix patterninto the selected surface to produce the modified data model.
 11. Themethod of claim 10, wherein the integrating the 3-D matrix pattern intothe selected surface comprises selectively eliminating material belowthe selected surface to form the 3-D matrix pattern.
 12. The method ofclaim 10, further comprising 3-D printing the component using themodified data model.
 13. The method of claim 10, wherein the integratingthe 3-D matrix pattern into the selected surface comprises selectivelyadding material above the selected surface portion to form the 3-Dmatrix pattern.
 14. The method of claim 13, further comprising 3-Dprinting the component using the modified data model.